Tapetum Lucidum/Walleye Biology
Perch, Walleye, Sauger and Saugeye, all have a Tapetum Lucidum. I am not sure if the Darters have a tapetum but they are in the Percidae (Perch) family as well. To see the members of the Pennsylvania darter family, click this link:
http://www.fish.state.pa.us/pafish/fishhtms/chap23.htm
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Info about the Tapetum, click the link: http://en.wikipedia.org/wiki/Tapetum_lucidum
Walleye have two very large eyes, from which this fish aptly derives its' name. The walleye can see many colours, but is colour blind to some. The walleye has a light reflecting membrane called a ‘Tapetum lucidum', this special feature helps the walleye see very capably at night, and during low light conditions. The walleye has specially adapted scales called a ‘ctenoid' scale, and these give the walleye seemingly extra ‘traction' in the water.
Walleye spawn in the early spring, right after ice-out, and are very prolific. They may lay their eggs in the rapids of rivers, or on gravel-beds or shoals of lakes. The males usually reach the spawning beds before the females.
After spawning, walleye have a short ‘rest' period of about (usually) three days to a week, then they start feeding again with a vengeance.
Walleye prefer, and feed the most in the temperature range of 73 F. This can vary a few degrees, depending on the local of the water. The walleye is active in the winter, and can be caught out of very cold water. Once the temperature goes way over the preferred range, up into the low 80's, the walleye will become lethargic, and not feed quite as extensively. Generally though, the walleye is the most active in the summer months, when it does its' most feeding - and growing. Generally, walleye grow much more slowly in its most northerly range, and much quicker in the southern duration of its range.
In addition to phenomenal sight, walleye also make use of superb hearing, both from the ears in its head, and the lateral line. A walleye can hear a single minnow up to 20 feet away - and tell if it is ‘acting' normally - or ‘crippled'
The walleye has a great sense of ‘smell' and uses this ‘sense' to help it find/capture its food.
Walleye are very migratory, and will travel great distances to find its' preferred temperature preference, food, and for spawning purposes.
The walleye is not a ‘darting' type fish, such as a sunfish, crappie, or pike, but can swim far and fast, seemingly chasing down its prey.
The walleye is an opportunist, and will eat voraciously during the warm summer months. The walleye eats primarily insects as a ‘walleye puppy', but most walleye eat predominantly minnows after the second year. They will eat nearly any species of minnows, and I've found they switch from relatively warm water varieties of minnows, about mid summer, to colder water minnow species, and will feed on these cold water species for the rest of the year. Walleye love smelt, but they also eat mooneyes, fatheads, emerald shiners; walleye are only rarely cannibalistic.
